I don’t have any objections to numbers greater than two.

I think the term “marriage” should either apply to all of them or none of them. I don’t think it’s acceptable for the law to recognize “marriage” between heterosexual couples and “something else” for others.

I think it would be acceptable for the government to stop calling all of them “marriages”, and only offer “civil unions” or whatever, but the same term should apply to all, precisely because the intent is that they are equivalent. Using separate language is just an invitation to future inequality.